Harmon Accentra-2 Pellet stove, status indicator light Blinks twice

Hi Don
I have a Harmon Pellet Stove-2, stand alone. Serial number 008400822
The manual is number 3-90-08326.
I completed the annual cleaning last fall following the maintenance procedures listed on pages 20 through 23.
This year the status light blinks twice, the auger will NOT come on.
I removed the low Draft Sensor.
I cleaned the sensor
I checked the micro-switch, it is normally open, it was, I verified with a multimeter.
I checked the vacuum hose from the switch to the bottom of the hopper, I could hear air inside the hopper, so the hose is free from obstruction.

I did NOT see the filter located inside the hopper, (known as the muffler) on page 22

My unit does not appear to have one of these.
On the bottom of the hopper, where the pellets go in is a sliding metal plate that moves freely by hand, but does not move when the unit is turned on.
My question is should I start by replacing the vacuum pressure switch 3-20-6866 or is there a better starting point?
Peter

I found the problem
The sliding metal plate is attached to the top of the Flapper located inside the (Feeder chamber) located behind the stove, part of the annual cleaning, in short, the must be put back together carefully after cleaning.
Peter

Hello
Yes the slide plate cannot be put in upside down because there is a lip that pushes the pellets into the auger chute. On the other end is a slot in the slide plate that must be hooked into the linkage that moves with the auger motor. Good work,